“Antietam’s the most evocative and scary battle site I’ve ever been to, and the only place I’ve ever felt a ‘presence,’” says John Barton, a Virginia photographer and Civil War junkie. “Much is the same as that day: there are still surrounding farms and unspoiled views of the Blue Ridge, so seeing the famous landmarks — the Cornfield, the Sunken Road — has a devastating power.”

Millions of Americans seek out that kind of visceral connection at Civil War sites annually, and the next few years are the time to visit as special events commemorate the conflict’s 150th anniversary. The National Park Service set up a dedicated website and launched a Twitter feed, @CivilWarReportr, that tracks the war’s development (“June 27, 1862: Our line gives way! We flee for the bridges to our rear as the cavalry attempts to stop the advance and save our artillery”; “July 7: A found newspaper reports the Federals have levied a tax on income above $600. Someone must pay for this war”).

For play-by-play commentary on the battlefield, you can hire an NPS-licensed guide at Gettysburg or Vicksburg to ride along for two-hour car tours. Parks also typically offer self-guided tours and orientation films and, on summer weekends, invite reenactors to stage skirmishes, decked out with muskets and wool uniforms. Check park websites to schedule your visit to coincide with the reenactments (or not — a few lonesome hours spent walking the battlefields can be at least as instructive).

The savagery leading up to the war demands revisiting, too: the Slave Trail in Richmond, Va., goes past slave markets, burial grounds and the Devil’s Half-Acre, a jail for “uncooperative” slaves (operated by a man married to a free African American wife!). In Harpers Ferry, W.V., the righteous anger of those who opposed slavery is palpable at John Brown’s Fort, where a band of abolitionists held federal troops at bay.

You don’t need to be a history buff to get caught up by these vivid stories. So whether you’re planning a road trip dedicated to the Civil War, or just detouring on the way elsewhere, be warned: you may be in for a lifelong obsession.